The Chemical Concerns in Denim Manufacturing

Posted by
Tellason
on April 13, 2015

The mass manufacturing of clothing is a hot topic in terms of workers’ rights and safety. In terms of mass-producing blue jeans, the process can be dangerous and even life threatening for blue jeans factory workers.
Sandblasting, an artificial method of distressing jeans, has been a safety concern since the 1990's when the distressed denim look became high in demand.
However, there are other concerns around the chemicals used to finish the
distressing process. Two chemicals that are often cited as potential health risks
are potassium permanganate and sodium metabisulphate.

What is potassium permanganate?

Potassium permanganate, or KMnO
4, is a powerful
oxidizing agent. A KMnO
4 spray is used to lighten the sandblasted
areas of distressed denim, giving them a worn, aged look.

What is sodium metabisulphate?

Sodium metabisulphate is another bleaching agent. Because
potassium permanganate often produces a light brown color when applied to
denim, sodium metabisulphate is used as a neutralizer to turn those areas
closer to a shade of white. The result is the appearance of sun-bleaching or
fading on the denim.

Why are they dangerous?

Potassium permanganate can dye most organic material, including skin. Worse, it can irritate or burn your skin or eyes if you come into direct contact with it. Permanent eye damage is possible.

Exposure to pure sodium metabisulphate can irritate your
respiratory tract, causing asthma-like symptoms. Ingesting it may cause nausea,
diarrhea, and other gastrointestinal problems while contact with the skin can
cause redness, pain, and itching. Sodium metabisulphate can also cause
permanent damage to your eyes after direct contact. Potassium
permanganate is also very volatile.

Any contact between potassium permanganate
and oxidizable substances, including simple alcohols, can result in violent
combustion. Lastly, potassium permanganate can irritate the nose and lungs.
High exposure levels can even cause pulmonary edema.

The lack of proper ventilation systems, protective gear
(such as goggles, masks, and gloves), and adequate procedural training for
factory workers makes the use of these chemicals extremely risky for their
short-term and long-term health.